Always create a default study group for new consumers

spec/models/consumer_spec.rb

@@ -4,6 +4,7 @@ require 'rails_helper'
 
 describe Consumer do
   let(:consumer) { described_class.create }
+  let(:valid_consumer) { create(:consumer) }
 
   it 'validates the presence of a name' do
     expect(consumer.errors[:name]).to be_present
@@ -21,4 +22,8 @@ describe Consumer do
   it 'validates the presence of an OAuth secret' do
     expect(consumer.errors[:oauth_secret]).to be_present
   end
+
+  it 'creates a study group after creation' do
+    expect(valid_consumer.study_groups.count).to eq 1
+  end
 end